advice/ personal experiences welcome!

Hello! I am 6 weeks pregnant. I am also 22 years old and just recently gotten married. This is my first pregnancy and every since I saw the positive on the hpt I can't shake the feeling that I might not have this baby. My sister and her husband and my sister and brother in law have been trying for 10 years combined to get pregnant. What are the chances my husband and I get pregnant the first time we don't use protection. I've been having cramping but no bleeding and every other pregnancy sign, nasuea, bloating, sore boobs. But I feel like I'm going to miscarry. I could just be worried because it's my first but then I think, what about my mothers intuition? I'm not sure if it's in my head or not and was wondering if you ladies feel the same way with your 1st? If you did feel this way did your pregnancy end up in a miscarriage?